Quick hitches for three point hitches of work machines such as tractors for agriculture, construction, and earth moving, for receiving and releasably holding a pin, such as a pin of an implement or other work element, are well known time saving devices.
Reference Schlegel et al. U.S. Pat. No. 6,349,959 B2 which discloses an exemplary quick hitch including couplers having a self-latching capability. However, couplers such as this rely on a force exerted by a spring to maintain a latch of the coupler in its closed or latched position, including in opposition to forces and movements exerted by a pin latched in the coupler operating in directions for opening the latch.
Relying on a spring force for maintaining a coupler in a latched condition can be disadvantageous. For instance, forces can be exerted by a work element through one or more pins held in a coupler in opposition to the spring force to urge the latch to partially or fully open. The pin can also be rotated while in forceful contact with the latch in a direction for moving the latch to its open position. For instance, as a tractor pulling an implement using a quick hitch is driven through a depression such as a ditch or swail in a field, the rear end of the tractor can be abruptly lowered relative to the implement being towed, such that pins of the implement are brought into contact with the latches of the couplers holding the pins and the pins simultaneously rotated in a direction for opening the latch, such that the latch can be partially opened.
Reference also von Allworden U.S. Pat. No. 3,977,698 issued Aug. 31, 1976 which discloses a hitch coupler including an exemplary locking latching mechanism for holding the latch in its closed position. However, such mechanism relies on interlocking components to provide the locking capability, which can be disadvantageous as the components add complexity and cost, and the interlocking capability can be degraded as the components wear and corrode.
Thus, what is sought is a hitch coupler, particularly a quick hitch for three point hitches of work machines such as tractors and the like, which includes a latching mechanism which can be both self-latching and self-locking, and overcomes one or more of the problems and disadvantages set forth above, and is simple in construction and advantageous cost-wise.